Centrifugal apparatus for dust extraction



Feb. 14, 1933. P H WDEN 1,897,195

CENTRIFUGAL APPARATUS FOR DUST EXTRACTION Filed June 5, 1930 2 Sheets-Sheet l Feb. 14, 1933. P. HOWDEN CENTRIFUGAL APPARATUS FOR DUST EXTRACTION Filed June 5, 1930 ZSheetsl-Sheet 2 Q INVENTOR. JbMNW ar M. v

Patented Feb. 14, 1933 ticles 0 UNITED STATEShPATENT OFFICE PETER HOWDEN, 0F HALIFAX ENGLAND, ASSIGNOR T0 BRITISH REMA MANUFAC- TUBING- CO., LTD., OF HALIFAX, ENGLAND, A CORPORATION OF GREAT BRITAIN CENTRIFUGAL APPARATUS FOR DUST EXTRACTION Application filed June 5, 1930, Serial No. 459,309, and in Great Britain July 18, 1929.

This invention relates to dust extraction in which more or less powdered material is car ried by an air or other fluid current hereinafter referred to as air through centrifugal apparatus of the cyclone separator type, which separates the finer material hereinafter referred to as dust, from the coarser material, and the present invention has for its chief object to enable superfine dust to be extracted, that is to say dust in which the particles are to all intents uniform in size, and in which no oversize particles occur such as would be detrimental in certain manufactures, for example in the manufacture of paints, ramophone records, and other arfineness is of extreme importance. The invention also has for its object to enable different grades of dust to be extracted in one machine, and which may vary from superfine to coarse, and with all the particles 1n any one grade of a practically uniform size.

A further object of this invention is to enable air containing dust to be cleaned. In this case the apparatus issuitably pro ortioned to give maximum extraction e ect, and the air made to release the dust entrained therein. If desired the process of grading the dust into several classes of product, say fine, medium, and coarse, may be combined with the process of finally cleaning the air.

According to this invention, dust of a uniform character is obtained by reventing over-size particles. which have en separated from the dust laden air in any stage by cyclonic or whirling action from remixing with the dust laden air in its passage to the outlet, or from one stage of the separating rocess to another, the air being led in a swir ing manner from an outer cylindrical chamber through ports in an inner cylindrical chamber or chambers, all of which are extended downwards to form delivery chutes for the particles of material rejected in each successive chamber. a The arrangement of the extended portion of "such chambers is such that no substantial quantity of air can pass from one chamber to another excepting through the ports in the upper portion. The

ports may be fitted with vanes to augment commerce where a uniformity of the swirling'motion of the air set up pri-,

or alternatively the vanes may be so arranged as to ive different directions offiow in each cham er. It is most important, however, that the air fiow is continuously directed towards the centre in its passage from the'outside chamber to the inner chamber or chambers and away from the rejected particles of dust which tend to swirl outwardly to the internal periphery of each chamber. By this method most eiiicient extraction is obtained as the kinetic energy in the dust particles tends to force these in the path of maximum radius whilst the air current is led to the centre of the apparatus in a path diminishing in radius. By this means, once a particle is rejected it is carried by its kinetic energy out of the air stream and has no means of re-entering same.

This invention overcomes the disadvantages of apparatus of similar type wherein an attempt is made to separate the material from the air by resorting to baifle plates or sharp changes of direction of flow or alternating increase and decrease of area of the passages through which the air flows, all of which set up turbulent action or eddies which largely counteract any separating action obtained by such devices. It also overcomes the disadvantages of separators of the cyclone, type where an open-ended cylinder is fitted inside another, the air in such apparatus travelling in a downward spiral direction with decreasing swirling motion in the same chamber as the rejected particles thereby allowing re-mixing to take place.

In the accompanyingv drawings 2-- Fig. 1 is a side elevation, partly in section, of an-embodiment of the invention;

Fig. 2 is a horizontal sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view of a modified form of the invention; and

Fig. 4 is a horizontal sectional view taken on the line 44 of Fig. 3.

In Fi s. 1 and. 2, an outer chamber A, an intermediate chamber E and an inner cham er B are employed, the air with the maerial to be separated entering the outermost chamber A tangentially at or near the top, passing to the next chamber E through ports e which may be provided'with pivoted vanes e circulating around such intermediate 1-0 chamber, passing' to the next chamber B e in the precedin chamber. The air containing the super --capes through an axially arran ed passage 15 C, the lower end of which is pre erably situated above the ports 6 in the chamber B. The coarser separated materials gravitate downwardly through the conical extensions a e b? of their respective chambers and pass to the discharge aperture a forcollection or retreatment in the manner previously dethrou'gh ports I) provided with ivoted vanes 12 preferably at a higher level t an the ports e powder ultimately essignature.

- I PETER HOWDEN.

scribed. The lower ends of the chambers B and E are closed by weighted flaps D. If the apparatus is to e used for obtaining the bottom of each conical 'chamber 6 b may lead to a separate collector e 12 instead of the bottom of the inner chambers being fitted with weighted flaps or the like'to discharge finally into the outer chamber. If it is desired to combine the grading or separating of powders with the action of finally cleaning the air, the a paratus may-be the same as thatshown in sired to use the apparatus for cleaning the air without gradin the powders the branch outlets e b may%1 valves, or flaps substituted. Where two sets of vaned ports are used in any application they may deflect air in the same direction as shown in Fig. 2 or in opposite directions as shown in Fig. *1.

The apparatus described may be used by form oi separator and it can be usedeither grindin which o veyed by an air current.

cleaning dust laden air, the number of chambers an their proportions aresuch that even the finest dust is rejected before the air reaches the outlet.

What I claim as my invention and desire to secure by Letters Patent in the United States is 1. A separator-and grader comprising ini I ner, intermediate and outer cones, vanes at the upper portions of the intermediate and inner cones providing communication with the outer an intermediate cones respectivee omitted and suitable itself or 1n combination with any existing Where the apparatus is to be used for graded powders as shown in Figs. 3 and 4 igs. 3 and 4. If it is de- I b lg, the vanes ofthe'intermediate cone-being.

sposed' substantially below the values m g N the inner cone, a tangential inlet adjacent the 

